Great reply and yeah, it's a tight build. I've been really pushing the limits on my template and have spent a fortune in the process. In fact I don't think I can even call my Sampire a Sampire anymore but he absolutely destroys without ever feeling vulnerable now.
you can't really get there without EoO
Yeah you can, I hit the 300% mark without a slayer(100% DI on gear + 120 anat + 120 tactics +150 str =288%). I added 60 LJ to hit 300 even and tested EoO, it gave me exactly 0 increased damage so it is stuck under the cap. I since removed LJ completely, turns out there are better skills to use the points on

Something else I noticed was that bushido, with my current gear(insanely expensive, built around 2 RNG Legendary pieces that cost 300m each), was also not worth its weight damage wise. I better understand the mechanics now and honoring a creature to build up the damage from consecutive strikes was also giving me no bonus anymore so it is also under cap. Lightning strike hit chance increase was wasted since the gear has cap of that as well. The lightning strike damage bonus(200% or so) did occasionally kick in but too infrequently for my liking so I removed Bushido to keep testing.
From there I questioned Parrying since without Bushido I'd need a shield and I ended up replacing it with healing, damage blocked and damage healed come out as a wash though healing has the added benefit of fairly frequent mid-heal cures that don't block the heal itself. When the healing attempt reaches the 50% of timer mark it makes a cure attempt... I got hooked on that. I also like that if I finish a fight low on health I am not stuck waiting to regen a bit(no chiv), the heal tops me up fast.
So at that point I had the following as base. Skill cap is 780 with my gear.
120 swords
120 tactics
120 anat
100 healing
100 necro
POISONING: I used a 2h double Axe as weapon for double strike and whirlwind and kept messing with other skills and eventually found I really liked poisoning on him. The poisoning mastery, via injected strike, lets you hit lethal poison 100% of the time at gm skill on anything not resistant or immune to it. The best part is that it works on non-infecting weapons like my axes and also debuffs the target to poison! It doesn't go off, or waste charges, unless you toggle the injected strike ability which is also nice and even then it applies regularly without using charges. I like the poisoning mastery a lot right now, it works great with Anatomy.
For the last 120 pts I usually go with 120 resist but have to admit that I now swap in 120 Chiv instead depending on situation, I have a full set of lesser slayers but where there are mixed type spawns it's easier to go with consecrate. I suppose I could go with something like 60/60 but that's laziness, I already have 120 of each and a soulstone + I like consecrate to last a little longer, it already wears off too fast imo. Neither of these skills is a factor in most situations though so I'm still trying to find something I like more with that last 120 pts. No luck yet.
I'm not done yet, but happy with a balanced character and faster kills(+poison) with healing more than makes up for parrying, imo. I don't miss the parrying damage mechanics either. If you don't have hundreds of millions to spend however I wouldn't recommend this build to anyone, every piece is expensive. It also suits my playstyle and preferred locations well but might bomb with yours, testing and retesting is key.
Tip: Make sure your real skill hits 100. 90+30 is not the same as 100+20 due to how the extra damage amount is added for having 100 skill. If you have 90+30, for example, you don't get the bonus with some skills.
EDIT for clarification: 100% poisoning with the mastery skill at level 3 and deadly poison placed on your weapon with inJected strike = Deadly Poison damage, not lethal. You only get lethal with a inFected strike weapon. Not only that but you probably want to have 100 poisoning and not 90 poisoning otherwise you're going to fail a LOT trying to poison a 2h axe, for example.